Emission of nitrous oxide (NaO) from unsterilized and NH, + treated Andosol was slightly increased by the addition of NOj-. This effect decreased with decrease in the amounts of NOa-added. Emission of NaO from unsterilized or sterilized soil treated with NHaOH was slightly increased by the addition of NOa-. Nitrous oxide can be produced through the reaction of hydroxylamine with nitrite in soil, though this reaction does not appear to be the main mechanism for the production of NaO in soil.